Set up the volume of everything else to match the drumset (unmic'ed). Usually it'll be a large combo (x2 speakers) or a halfstack and a loud enough bass amp. The pa system will be loud enough to cut through the mix. Remember that it's a band, not a competition to see who's the loudest and have the drummer control his playing dynamics. Also... put the pa speakers facing away from you and the mic's (cardoid or hopefully supercardoid pattern if possible) back part facing the speakers to prevent feedback. Also try to keep the amps, particularly the guitar ones, away from the guitars to reduce feedback as well.

I use a small 100w PA for vocals, keys, and acoustic at practice. Bass and electric are in amps. We keep it all pretty quiet though-- If a 15 watt (tube) combo isnt loud enough, then you're hurting your hearing unless you wear earplugs.

Set up the volume of everything else to match the drumset (unmic'ed). Usually it'll be a large combo (x2 speakers) or a halfstack and a loud enough bass amp. The pa system will be loud enough to cut through the mix. Remember that it's a band, not a competition to see who's the loudest and have the drummer control his playing dynamics. Also... put the pa speakers facing away from you and the mic's (cardoid or hopefully supercardoid pattern if possible) back part facing the speakers to prevent feedback. Also try to keep the amps, particularly the guitar ones, away from the guitars to reduce feedback as well.

This. Usually one guitar on either side of the drums as well, and bass on one side or the other (usually same as the designated lead guitarist).

Set up the volume of everything else to match the drumset (unmic'ed). Usually it'll be a large combo (x2 speakers) or a halfstack and a loud enough bass amp. The pa system will be loud enough to cut through the mix. Remember that it's a band, not a competition to see who's the loudest and have the drummer control his playing dynamics. Also... put the pa speakers facing away from you and the mic's (cardoid or hopefully supercardoid pattern if possible) back part facing the speakers to prevent feedback. Also try to keep the amps, particularly the guitar ones, away from the guitars to reduce feedback as well.

A different way to do it is to set up your speakers like you would monitors, facing the band. Just set them on the floor with the speakers angled up toward the vocals, then add a monitor for the drummer and anyone else if you need to. Just as a rule of thumb don't point any mic's at PA speakers.

we use a drumkit and guitar amps, a 65 watt combo and a 120 watt halfstack, both SS (although my singing guitarist left the band). our bassist also had a 100 watt bass amp, but she left as well. vocals and keyboard go through a keyboard 200 watt amp.